Remove unnecessary use of PQExpBuffer.

StringInfo is more appropriate in backend code. (Unless the buffer needs to
be used in a thread.)

In the passing, rename the 'conn' static variable in cdbfilerepconnclient.c.
It seemed overly generic.

src/backend/cdb/cdbbackup.c

@@ -15,8 +15,6 @@
 
 #include "regex/regex.h"
 #include "libpq/libpq-be.h"
-#include "gp-libpq-fe.h"
-#include "gp-libpq-int.h"
 #include "fmgr.h"
 #include "funcapi.h"
 #include "utils/builtins.h"
@@ -60,7 +58,7 @@ static char* parse_prefix_from_params(char *params);
 static char* parse_status_from_params(char *params);
 static char* parse_option_from_params(char *params, char *option);
 static char *queryNBUBackupFilePathName(char *netbackupServiceHost, char *netbackupRestoreFileName);
-static char *shellEscape(const char *shellArg, PQExpBuffer escapeBuf, bool addQuote);
+static char *shellEscape(const char *shellArg, bool addQuote);
 
 
 #ifdef USE_DDBOOST
@@ -316,8 +314,6 @@ gp_backup_launch__(PG_FUNCTION_ARGS)
 		}
 	}
 
-	PQExpBuffer escapeBuf = NULL;
-
 	pszDBName = NULL;
 	pszUserName = (char *) NULL;
 	if (MyProcPort != NULL)
@@ -330,13 +326,7 @@ gp_backup_launch__(PG_FUNCTION_ARGS)
 		pszDBName = "";
 	else
 	{
-		/*
-		 * pszDBName will be pointing to the data portion of the PQExpBuffer
-		 * once escpaped (escapeBuf->data), so we can't safely destroy the
-		 * escapeBuf buffer until the end of the function.
-		 */
-		escapeBuf = createPQExpBuffer();
-		pszDBName = shellEscape(pszDBName, escapeBuf, true);
+		pszDBName = shellEscape(pszDBName, true);
 	}
 
 	if (pszUserName == NULL)
@@ -996,8 +986,6 @@ gp_backup_launch__(PG_FUNCTION_ARGS)
 
 	assert(pszSaveBackupfileName != NULL && pszSaveBackupfileName[0] != '\0');
 
-	destroyPQExpBuffer(escapeBuf);
-
 	return DirectFunctionCall1(textin, CStringGetDatum(pszSaveBackupfileName));
 }
 
@@ -1223,7 +1211,6 @@ gp_restore_launch__(PG_FUNCTION_ARGS)
 
 	len_name = strlen(pszBackupFileName);
 
-	PQExpBuffer escapeBuf = NULL;
 	pszDBName = NULL;
 	pszUserName = NULL;
 	if (MyProcPort != NULL)
@@ -1235,15 +1222,7 @@ gp_restore_launch__(PG_FUNCTION_ARGS)
 	if (pszDBName == NULL)
 		pszDBName = "";
 	else
-	{
-		/*
-		 * pszDBName will be pointing to the data portion of the PQExpBuffer
-		 * once escpaped (escapeBuf->data), so we can't safely destroy the
-		 * escapeBuf buffer until the end of the function.
-		 */
-		escapeBuf = createPQExpBuffer();
-		pszDBName = shellEscape(pszDBName, escapeBuf, true);
-	}
+		pszDBName = shellEscape(pszDBName, true);
 
 	if (pszUserName == NULL)
 		pszUserName = "";
@@ -1465,8 +1444,6 @@ gp_restore_launch__(PG_FUNCTION_ARGS)
 
 	assert(pszBackupFileName != NULL && pszBackupFileName[0] != '\0');
 
-	destroyPQExpBuffer(escapeBuf);
-
 	return DirectFunctionCall1(textin, CStringGetDatum(pszBackupFileName));
 }
 
@@ -2473,40 +2450,39 @@ static char *formDDBoostFileName(char *pszBackupKey, bool isPostData, bool isCom
  * escaped.
  *
  * This function escapes the following characters: '"', '$', '`', '\', '!', '''.
- *
- * The StringInfo escapeBuf is used for assembling the escaped string and is reset at the
- * start of this function.
  */
 char *
-shellEscape(const char *shellArg, PQExpBuffer escapeBuf, bool addQuote)
+shellEscape(const char *shellArg, bool addQuote)
 {
-        const char *s = shellArg;
-        const char      escape = '\\';
+	const char *s = shellArg;
+	const char      escape = '\\';
+	StringInfoData escapeBuf;
 
-	resetPQExpBuffer(escapeBuf);
+	initStringInfo(&escapeBuf);
 
 	if (addQuote)
-		appendPQExpBufferChar(escapeBuf, '\"');
-        /*
-         * Copy the shellArg into the escapeBuf prepending any characters
-         * requiring an escape with the escape character.
-         */
-        while (*s != '\0')
-        {
-                switch (*s)
-                {
-                        case '"':
-                        case '$':
-                        case '\\':
-                        case '`':
-                        case '!':
-                                appendPQExpBufferChar(escapeBuf, escape);
-                }
-                appendPQExpBufferChar(escapeBuf, *s);
-                s++;
-        }
+		appendStringInfoChar(&escapeBuf, '\"');
 
-	if(addQuote)
-		appendPQExpBufferChar(escapeBuf, '\"');
-        return escapeBuf->data;
+	/*
+	 * Copy the shellArg into the escapeBuf prepending any characters
+	 * requiring an escape with the escape character.
+	 */
+	while (*s != '\0')
+	{
+		switch (*s)
+		{
+			case '"':
+			case '$':
+			case '\\':
+			case '`':
+			case '!':
+				appendStringInfoChar(&escapeBuf, escape);
+		}
+		appendStringInfoChar(&escapeBuf, *s);
+		s++;
+	}
+
+	if (addQuote)
+		appendStringInfoChar(&escapeBuf, '\"');
+	return escapeBuf.data;
 }

src/backend/cdb/cdbcopy.c

@@ -12,7 +12,6 @@
 
 #include "postgres.h"
 #include "gp-libpq-fe.h"
-#include "gp-libpq-int.h"
 #include "miscadmin.h"
 #include "cdb/cdbconn.h"
 #include "cdb/cdbcopy.h"

src/backend/cdb/cdbfilerepconnclient.c

@@ -13,6 +13,7 @@
  *
  */
 #include "postgres.h"
+
 #include <signal.h>
 
 #include "cdb/cdbvars.h"
@@ -20,10 +21,10 @@
 #include "cdb/cdbfilerepconnclient.h"
 #include "gp-libpq-fe.h"
 #include "gp-libpq-int.h"
-#include "pqexpbuffer.h"
 #include "cdb/cdbfilerepservice.h"
 
-static PGconn	*conn = NULL;
+static PGconn	*filerep_conn = NULL;
+
 /*
  *
  */
@@ -34,51 +35,52 @@ FileRepConnClient_EstablishConnection(
 	bool	reportError)
 {
 	int			status = STATUS_OK;
-	PQExpBuffer	buffer = NULL;
-	
+	char		portbuf[11];
+	char		timeoutbuf[11];
+	const char *keys[5];
+	const char *vals[5];
+
 /*	FileRepConnClient_CloseConnection();*/
-	
-	buffer = createPQExpBuffer();
 
-	if (PQExpBufferBroken(buffer))
-	{
-		destroyPQExpBuffer(buffer);
-		/* XXX: allocation failed. Is this the right thing to do ? */
-		return STATUS_ERROR;
-	}
+	snprintf(portbuf, sizeof(portbuf), "%d", port);
+	snprintf(timeoutbuf, sizeof(timeoutbuf), "%d", gp_segment_connect_timeout);
+
+	keys[0] = "host";
+	vals[0] = hostAddress;
+	keys[1] = "port";
+	vals[1] = portbuf;
+	keys[2] = "dbname";
+	vals[2] = "postgres";
+	keys[3] = "connect_timeout";
+	vals[3] = timeoutbuf;
+	keys[4] = NULL;
+	vals[4] = NULL;
 
-	appendPQExpBuffer(buffer, "host=%s ", hostAddress);	
-	appendPQExpBuffer(buffer, "port=%d ", port);
-	appendPQExpBuffer(buffer, "dbname=postgres ");
-	appendPQExpBuffer(buffer, "connect_timeout=%d", gp_segment_connect_timeout);
-	
-	conn = PQconnectdb(buffer->data);
+	filerep_conn = PQconnectdbParams(keys, vals, false);
 
-	if (PQstatus(conn) != CONNECTION_OK) {		
+	if (PQstatus(filerep_conn) != CONNECTION_OK)
+	{
 		if (reportError || Debug_filerep_print)
 			ereport(WARNING, 
 					(errcode_for_socket_access(),
 					 errmsg("could not establish connection with server, host:'%s' port:'%d' err:'%s' : %m",
 							hostAddress,
 							port,
-							PQerrorMessage(conn)),
+							PQerrorMessage(filerep_conn)),
 					 errSendAlert(true),
 					 FileRep_errcontext()));
-		
+
 		status = STATUS_ERROR;
-		
-		if (conn) {
-			PQfinish(conn);
-			conn = NULL;
+
+		if (filerep_conn)
+		{
+			PQfinish(filerep_conn);
+			filerep_conn = NULL;
 		}
 	}
-	
+
 	/* NOTE Handle error message see ftsprobe.c */
-	
-	if (buffer) {
-		destroyPQExpBuffer(buffer);
-		buffer = NULL;
-	}
+
 	return status;	
 }
 
@@ -88,11 +90,12 @@ FileRepConnClient_EstablishConnection(
 void
 FileRepConnClient_CloseConnection(void)
 {
-	if (conn) {
+	if (filerep_conn)
+	{
 		/* use non-blocking mode to avoid the long timeout in pqSendSome */
-		conn->nonblocking = TRUE;
-		PQfinish(conn);
-		conn = NULL;
+		filerep_conn->nonblocking = TRUE;
+		PQfinish(filerep_conn);
+		filerep_conn = NULL;
 	}
 	return;
 }
@@ -118,7 +121,7 @@ FileRepConnClient_SendMessage(
 	int status = STATUS_OK;
 
 #ifdef USE_ASSERT_CHECKING
-	int prevOutCount = conn->outCount;
+	int prevOutCount = filerep_conn->outCount;
 #endif // USE_ASSERT_CHECKING
 
 	switch(messageType)
@@ -143,12 +146,12 @@ FileRepConnClient_SendMessage(
 	 * Note that pqPutMsgStart and pqPutnchar both may grow the connection's internal buffer, and do not
 	 *   flush data
 	 */
-	if (pqPutMsgStart(msgType, true, conn) < 0 )
+	if (pqPutMsgStart(msgType, true, filerep_conn) < 0 )
 	{
 		return false;
 	}
 
-	if ( pqPutnchar(message, messageLength, conn) < 0 )
+	if ( pqPutnchar(message, messageLength, filerep_conn) < 0 )
 	{
 		return false;
 	}
@@ -156,23 +159,23 @@ FileRepConnClient_SendMessage(
 	/* Server side needs complete messages for mode-transitions so disable auto-flush since it flushes
 	 *  partial messages
 	 */
-	pqPutMsgEndNoAutoFlush(conn);
+	pqPutMsgEndNoAutoFlush(filerep_conn);
 
 	/* assert that a flush did not occur */
-	Assert( prevOutCount + messageLength + 5 == conn->outCount ); /* the +5 is the amount added by pgPutMsgStart */
+	Assert( prevOutCount + messageLength + 5 == filerep_conn->outCount ); /* the +5 is the amount added by pgPutMsgStart */
 
 	/*
 	 *                note also that we could do a flush beforehand to avoid
 	 *                having pqPutMsgStart and pqPutnchar growing the buffer
 	 */
-	 if (messageSynchronous || conn->outCount >= file_rep_min_data_before_flush )
+	 if (messageSynchronous || filerep_conn->outCount >= file_rep_min_data_before_flush )
 	{
 		int result = 0;
 		/* wait and timeout will be handled by pqWaitTimeout */
-		while ((status = pqFlushNonBlocking(conn)) > 0)
+		while ((status = pqFlushNonBlocking(filerep_conn)) > 0)
 		{
 			/* retry on timeout */
-			while (!(result = pqWaitTimeout(FALSE, TRUE, conn, time(NULL) + file_rep_socket_timeout)))
+			while (!(result = pqWaitTimeout(FALSE, TRUE, filerep_conn, time(NULL) + file_rep_socket_timeout)))
 			{
 				if (FileRepSubProcess_IsStateTransitionRequested())
 				{

src/backend/cdb/dispatcher/cdbdisp.c

@@ -386,7 +386,6 @@ cdbdisp_makeDispatcherState(CdbDispatcherState *ds,
 /*
  * Free memory in CdbDispatcherState
  *
- * Free the PQExpBufferData allocated in libpq.
  * Free dispatcher memory context.
  */
 void

src/backend/cdb/dispatcher/cdbgang.c

@@ -314,19 +314,15 @@ isPrimaryWriterGangAlive(void)
 /*
  * Check the segment failure reason by comparing connection error message.
  */
-bool segment_failure_due_to_recovery(struct PQExpBufferData* error_message)
+bool
+segment_failure_due_to_recovery(const char *error_message)
 {
-	char *fatal = NULL, *message = NULL, *ptr = NULL;
+	char *fatal = NULL, *ptr = NULL;
 	int fatal_len = 0;
 
 	if (error_message == NULL)
 		return false;
 
-	message = error_message->data;
-
-	if (message == NULL)
-		return false;
-
 	fatal = _("FATAL");
 	fatal_len = strlen(fatal);
 
@@ -338,14 +334,14 @@ bool segment_failure_due_to_recovery(struct PQExpBufferData* error_message)
 	 * the strings a lot we have to take extreme care with looking at
 	 * the string.
 	 */
-	ptr = strstr(message, fatal);
+	ptr = strstr(error_message, fatal);
 	if ((ptr != NULL) && ptr[fatal_len] == ':')
 	{
-		if (strstr(message, _(POSTMASTER_IN_STARTUP_MSG)))
+		if (strstr(error_message, _(POSTMASTER_IN_STARTUP_MSG)))
 		{
 			return true;
 		}
-		if (strstr(message, _(POSTMASTER_IN_RECOVERY_MSG)))
+		if (strstr(error_message, _(POSTMASTER_IN_RECOVERY_MSG)))
 		{
 			return true;
 		}

src/backend/cdb/dispatcher/cdbgang_async.c

@@ -179,7 +179,7 @@ create_gang_retry:
 						break;
 
 					case PGRES_POLLING_FAILED:
-						if (segment_failure_due_to_recovery(&segdbDesc->conn->errorMessage))
+						if (segment_failure_due_to_recovery(PQerrorMessage(segdbDesc->conn)))
 						{
 							in_recovery_mode_count++;
 							connStatusDone[i] = true;

src/backend/cdb/dispatcher/cdbgang_thread.c

@@ -403,7 +403,7 @@ checkConnectionStatus(Gang* gp, int* countInRecovery, int* countSuccessful, stru
 			ereport(LOG, (errcode(segdbDesc->errcode), errmsg("%s",segdbDesc->error_message.data)));
 
 			/* this connect failed -- but why ? */
-			if (segment_failure_due_to_recovery(&segdbDesc->error_message))
+			if (segment_failure_due_to_recovery(segdbDesc->error_message.data))
 			{
 				elog(LOG, "segment is in recovery mode (%s)", segdbDesc->whoami);
 				(*countInRecovery)++;

src/backend/utils/adt/ruleutils.c

@@ -55,7 +55,6 @@
 #include "utils/typcache.h"
 #include "utils/xml.h"
 #include "gp-libpq-fe.h"
-#include "pqexpbuffer.h"
 
 
 /* ----------

src/include/cdb/cdbgang.h

@@ -92,7 +92,7 @@ bool isPrimaryWriterGangAlive(void);
 Gang *buildGangDefinition(GangType type, int gang_id, int size, int content);
 void build_gpqeid_param(char *buf, int bufsz, int segIndex, bool is_writer, int gangId, int hostSegs);
 char *makeOptions(void);
-bool segment_failure_due_to_recovery(struct PQExpBufferData *segdbDesc);
+extern bool segment_failure_due_to_recovery(const char *error_message);
 
 /*
  * disconnectAndDestroyIdleReaderGangs()